Heat-resisting plate



Sept. 27, 1927.

A. FAHRENWALD HEAT RESISTING PLATE Filed April 21. 1926 Patented Sept.1927.

UNITED STATES A 1,643,766 PATENT OFFICE.

FRANK A. FAHRENWALD, OFCHICAGO HEIGHTS, ILLINOIS.

.nnl'r-nnsrs'rmo PLATE.

Application filed April 21, 1926. Serial No. 103,655.

This invention relates to plates used for providing heat-resistingmetallic surfaces, such, for instance, as furnace hearths, dampers, andthe like, and has for its object to provide a plate which will not crackor warp when subjected to unequal temperatures at different points inits area, or fluctuating temperatures as encountered in the average hightemperature, operations. 1 Attempts heretofore made to use plates in thesituations referred to have generally involved the use of solidone-piece plates, either of cast or rolled material, but themaintenanceof'fiat or unchanging metal surfaces, particularly whencarrying loads at high temperatures or when used for heat checkingpurposes, have involved the most trying difficulties because of theshort life of such members due to excessive warping and cracking. Inpractically all flat metal surfaces exposed to high temperatures, theheating of the member providing the surface is unevenly distributedthroughout the exposed area. Moreover, the temperature fluctuates fromtime to time, both in location and degree, and the expansion andcontraction attending these temperature fluctuations eventually causethe metal to crack or to buckle or Warp in accommodating itself thereto;and this occurs even in plates made of heat resisting alloys. For thesereasons, it is not economically practicable to pro: vide heat resistingsurfaces of large areas by a single piece plate.

In my Letters Patent No. 1,629,689, issued May 24; 1927, for heatresisting dampers and the like, disclosing by way of illustration amovable heat resisting barrier but including a construction applicableto heatresisting walls in general I have disclosed means by which toovercome the abovestated difficulty, and this is accomplished by makingheat-resisting plates, whether for use in providing hearth surfaceswhere they are mounted horizontally, or approximately horizontally, orfor dampers, or the like, where they are either mounted horizontally orsuspended or otherwise supported in substantially vertical position, ofan assembly of relatively small plates or members, so arranged withrespect one to another and to the whole area that the stresses caused bythermal expansion and contraction do not exceed a predetermined maximumat which the surfaces of the members will retain their original formindefinitely; these members being provided with means for maintainingthem in their predetermined relative positions in which theycollectively make up the whole surface required, without materialinterruption of the surface at the places where the members meet.

Since one of the principal difficulties encountered in making aheat-resisting plate of a plurality of separately formed membersassembled edge to edge, is in providing proper interengagement of themembers to interlock them and hold their edges in proper registrywithout interrupting or obstructing the working surface, the inventionof my said Letters Patent further consists in the provision ofoppositely extending interspaced projections or lugs which lie all onone and the same side of the plane of the wall, and preferably the sideopposite to the working surface, and at the meeting marglnal portions ofsaid members, so that each member carries one or more such lugs orprojections which cross the meeting edges and lap upon the adjacentmember, thereby avoiding displacement of each member in either directionperpendicular to the working surface.

Inasmuch as some uses of sectional plates embodying the presentinvention will render desirable the provision of means for interlockingthe separately formed members against relative displacement in the planeof the working surface, the present invention supplements the inventionof the said Letters Patent by constructing some of the interlockingparts for interengagement in the last-named direction in addition to theinterlock which they effect in the direction perpendicular to theWorking surface, this being accomplished, for instance, by providingslots in a suitable number of the lappmg lugs or projections, andproviding studs or dowel-like projections in registry with these slotson the members which the slotted lugs overlap.

In order that the invention may be fully understood, the preferredembodiment thereof is illustrated in the accompanying drawing, in which-Figure 1 is an outer face elevation of a multiple section plate, themembers of which are provided with means for interlocking them whenassembled edge to edge.

Figure 2 is an inner face elevation of the same, showing the workingsurface provided thereby.

- one of the constituent sections or members of theil plate separatedfrom the other members; an

Figures 7 and 8 are, respectively, a detail elev'ational view and atransverse section on the line 8 8 of Figure 7 showing the means forinterlocking the members against displacement in the plane of theworking surface.

1 represents end members and 2 intermediate members, of which latterthere may be any desired number assembled to produce a plate suitablefor forming the working surface of a heat resisting plate, for instance,a furnace hearth. These plat-es have on one side substantially smoothand unobstructed surfaces which collectively provide the area of workingsurface required, and upon their faces opposite to this working surface,each is provided with one or more lapping lugs or projections 4 integralwith the marginal portion, through which the member meets an adjacentmember. There are lapping lugs 4 on each member at each point 5, so thatneither member can move relatively to the other in a directionperpendicular to the working surface. In addition to the lapping lugs 4,a membermay carry on its marginal portion, other integral lapping lugs 6formed with slots 7, and the meeting marginal portion of an adjacentmember may be formed with integral studs or dowels 8 in position toenter the slots 7 and thereby hold the members against separation in thedirection of the plane of the working surface, see particularly Figures6, 7, and 8.

Preferably, the members are beveled or chamfered at their meeting edges5, as shown more clearly in Figure 8. For convenience in assembling themembers or plate sections,

the studs or dowels 8 may have such tolerance I of the plate section ormember as tofacilitate assembly, the lug being thereafter pressed intoparallelism with the plate.

Preferably, the plate sections-will be produced from heat-resistingalloy.

I claim:

1. A sectional heat resisting plate, comprising a plurality of platesections assembled in a plane edge to edge, the meeting marginal portionof each plate section at the line of meeting being provided with a. lugor lugs projecting therefrom in the direction of the plane of the plateand lapping'upon the plate section which meets it, the lugs on the twosections at each line of meeting being on the same side of the plane ofthe plate, and means being provided for interlocking the plate membersagainst separation in the direction of the plane of the plate.

2. A sectional heat resisting plate, com-' prising a plurality of platesections assembled in a plane edge to edge, the meeting marginal portionof each plate section at the line of meeting being provided with a lugor lugs projecting therefrom in the direction of the plane of the plateand lap ping upon the plate section which meets it,

the lugs on the two sections at each line of meeting being on the sameside of the plane of the plate, and means being provided forinterlocking the plate members against separation in the direction oftheplane of the plate, consisting of openings constructed in some of thelapping lugs and projections on marginal portions of adjacent sectionswhich enter said openings.

Signed at Chicago, Illinois, this 14th day of April, 1926.

FRANK A. FAHRENWALD.

